One important thing to remember is that adding a DD spell or a weapon to your minion will make your HF spawn IN FRONT of your minion.

Other than that, using a HF, you prey on people with AMF, since that is wasted experience against you. If you add a base decay, your enchanter may wind up hurting itself just enough that their AMF may be letting them win.

However, a base decay is such a small amount of experience, you might as well try it out at some point to see how it goes.